New Radio (NR) supports both codebook and non-codebook based uplink (UL) MIMO transmission. For codebook based UL MIMO, the transmission and reception point (TRP) measures uplink channels based on sounding reference signals (SRSs) sent by user equipment (UE) and determines the rank and the precoder for uplink transmission based on a predefined (standard related) codebook. After measuring the SRSs, the TRP indicates the rank and the precoder to the UE. For non-codebook based UL MIMO, no codebook is pre-specified in the specification of the 5G NR standard.